Messages in this thread | | | Date | Mon, 15 Jun 2015 23:18:16 +0200 | From | Michal Hocko <> | Subject | Re: Possible broken MM code in dell-laptop.c? |
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On Sun 14-06-15 11:05:07, Pali Rohár wrote: > Hello, > > in drivers/platform/x86/dell-laptop.c is this part of code: > > static int __init dell_init(void) > { > ... > /* > * Allocate buffer below 4GB for SMI data--only 32-bit physical addr > * is passed to SMI handler. > */ > bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); [...] > buffer = page_address(bufferpage); [...] > fail_rfkill: > free_page((unsigned long)bufferpage);
This one should be __free_page because it consumes struct page* and it is the proper counter part for alloc_page. free_page, just to make it confusing, consumes an address which has to be translated to a struct page.
I have no idea why the API has been done this way and yeah, it is really confusing.
[...] > static void __exit dell_exit(void) > { > ... > free_page((unsigned long)buffer);
-- Michal Hocko SUSE Labs
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